To explore the clinical efficacy and safety of lumbrokinase in the treatment of acute and moderate risk pulmonary thromboembolism. Methods: The clinical data of 60 patients with acute and moderate risk pulmonary thromboembolism, who were collected from January 2010 to October 2015 in Hunan Provincial People's Hospital, were retrospectively analyzed. According to the different treatments, 60 patients were randomly divided into a lumbrokinase group (lumbrokinase in combination with low molecular heparin and sequential warfarin, n=30) and a control group (low molecular heparin and sequential warfarin, n=30). The clinical efficacy and safety were compared between the two groups. Results: Compared with the control group, maximum short axis, ratio of right and left ventricles, systolic pulmonary artery pressure, and the main pulmonary artery diameter in the lumbrokinase group were significant changed after the treatment for 10, 20 and 30 d. NT-proBNP level in the lumbrokinase group after the treatment for 10, 20 and 30 d was significantly reduced than that in the the control group (P<0.05). However, the value of PO2 significantly increased after 10, 20 and 30 d, and there was no significant difference between 20 d and 30 d (P>0.05). D-dimer in the two groups was obviously increased after treatment for 10 d, but it was significantly reduced after treatment for 20 d or 30 d (P<0.05). The clinical efficacy of the lumbrokinase group was better than that in the control group, with significant difference (P<0.05). Conclusion: Combination of lumbrokinase with low molecular heparin and sequential warfarin is a safe and efficient strategy in treating the patients with acute and moderate risk pulmonary thromboembolism. It is worthy of clinical popularization and application.